APES

• El Niño (ENSO)


  prevailing winds in the Pacific weaken and change direction every few years which results in above average warming of eastern Pacific waters, which changes distribution of plant nutrients and alters earth's weather for 2-3 years
• Reason for seasons on Earth

  Tilt of the axis ~23.5°
• Second Law of Thermodynamics

  When energy is changed from one form to another, some useful energy is always degraded into lower quality energy (usually heat).
• Nuclear Fission


  nuclei of isotopes split apart when struck by neutrons.
• Leaching


  removal of dissolved materials from soil by water moving downwards through soil.
• Soil Conservation Methods


  conservation tillage, crop rotation, contour plowing, organic fertilizers.
• Soil Salinization


  in arid regions, water evaporates leaving salts behind. (ex. Fertile crescent, southwestern US)
• Hydrologic Cycle Components


  evaporation, transpiration, runoff, condensation, precipitation, and infiltration.
• Watershed


  all of the land that drains into a body of water
• Aquifer


  any water-bearing layer in the ground.
• Salt Water Intrusion


  near the coast, overpumping of groundwater causes saltwater to move into the aquifer.
• La Nina


  "Normal" year, easterly trade winds and ocean currents pool warm water in the western Pacific, allowing upwelling of nutrient rich water off the West coast of South America.
• Ammonification


  decomposers covert organic waste into ammonia.
• Nitrification


  ammonia is converted to nitrate ions (NO -).
• Assimilation


  inorganic N is converted into organic molecules such as DNA/amino acids & proteins.
• Denitrification


  bacteria convert ammonia back into N.
• Soil Profile

  
• Photosynthesis


  plants convert CO2 (atmospheric C) into complex carbohydrates (glucose C6H12O6).
• Aerobic Respiration


  oxygen consuming producers, consumers & decomposers break down complex organic compounds & convert C back into CO2.
• Biotic


  living components of an ecosystem.
• Abiotic


  nonliving components of an ecosystem
• Trophic Levels


  producers → primary consumer → secondary consumer → tertiary consumer.
• Energy Flow through Food Webs


  10% of the usable energy is transferred to the next trophic level. Reason: usable energy lost as heat (2nd law), not all biomass is digested & absorbed, predators expend energy to catch prey.
• Primary succession


  development of communities in a lifeless area not previously inhabited by life (ex. lava).
• Secondary succession


  life progresses where soil remains (ex. clear-cut forest, old farm).
• Mutualism


  symbiotic relationship where both organisms benefit (e.g. clownfish and anemone)
• Commensalism


  symbiotic relationship where one organism benefits & the other is unaffected (e.g. epiphytic plants, such as many orchids, that grow on trees)
• Parasitism


  relationship in which one organism (the parasite) obtains nutrients at the expense of the host (e.g. mosquitoes and humans)
• Carrying Capacity


  the number of individuals that can be sustained in an area.
• r-selected species


  reproductive strategy in which organisms reproduce early, bear many small, unprotected offspring (ex. insects, mice).
• K-selected species


  reproductive strategy in which organisms reproduce late, bear few, cared for offspring (ex. humans, elephants).
• Natural Selection


  organisms that possess favorable adaptations (through mutations) pass them onto the next generation.
• Doubling Time


  (rule of 70) doubling time equals 70 divided by average growth rate. (ex. a population growing at 5% annually doubles in 70 ÷ 5 = 14 years)
• Replacement Level Fertility


  the number of children a couple must bear to replace themselves (2.1 developed, 2.7 developing).
• World Population


  slightly over 7.8 billion.
• Demographic Transition Model


  preindustrial, transitional, industrial, and postindustrial stages

  
• Preindustrial stage


  birth & death rates high, population grows slowly, infant mortality high.
• Transitional stage


  Aid from other countries and increase in industrialization lowers death rates (infant mortality). Birth rates high (from of the amount of people in the reproductive stage).
• Industrial stage


  decline in birth rate, population growth slows.
• Postindustrial stage


  low birth & death rates.